1/*
2 * fs/nfs/nfs4session.h
3 *
4 * Copyright (c) 2012 Trond Myklebust <Trond.Myklebust@netapp.com>
5 *
6 */
7#ifndef __LINUX_FS_NFS_NFS4SESSION_H
8#define __LINUX_FS_NFS_NFS4SESSION_H
9
10/* maximum number of slots to use */
11#define NFS4_DEF_SLOT_TABLE_SIZE (64U)
12#define NFS4_MAX_SLOT_TABLE (1024U)
13#define NFS4_NO_SLOT ((u32)-1)
14
15#if IS_ENABLED(CONFIG_NFS_V4)
16
17/* Sessions slot seqid */
18struct nfs4_slot {
19	struct nfs4_slot_table	*table;
20	struct nfs4_slot	*next;
21	unsigned long		generation;
22	u32			slot_nr;
23	u32		 	seq_nr;
24	unsigned int		interrupted : 1;
25};
26
27/* Sessions */
28enum nfs4_slot_tbl_state {
29	NFS4_SLOT_TBL_DRAINING,
30};
31
32#define SLOT_TABLE_SZ DIV_ROUND_UP(NFS4_MAX_SLOT_TABLE, 8*sizeof(long))
33struct nfs4_slot_table {
34	struct nfs4_session *session;		/* Parent session */
35	struct nfs4_slot *slots;		/* seqid per slot */
36	unsigned long   used_slots[SLOT_TABLE_SZ]; /* used/unused bitmap */
37	spinlock_t	slot_tbl_lock;
38	struct rpc_wait_queue	slot_tbl_waitq;	/* allocators may wait here */
39	u32		max_slots;		/* # slots in table */
40	u32		max_slotid;		/* Max allowed slotid value */
41	u32		highest_used_slotid;	/* sent to server on each SEQ.
42						 * op for dynamic resizing */
43	u32		target_highest_slotid;	/* Server max_slot target */
44	u32		server_highest_slotid;	/* Server highest slotid */
45	s32		d_target_highest_slotid; /* Derivative */
46	s32		d2_target_highest_slotid; /* 2nd derivative */
47	unsigned long	generation;		/* Generation counter for
48						   target_highest_slotid */
49	struct completion complete;
50	unsigned long	slot_tbl_state;
51};
52
53/*
54 * Session related parameters
55 */
56struct nfs4_session {
57	struct nfs4_sessionid		sess_id;
58	u32				flags;
59	unsigned long			session_state;
60	u32				hash_alg;
61	u32				ssv_len;
62
63	/* The fore and back channel */
64	struct nfs4_channel_attrs	fc_attrs;
65	struct nfs4_slot_table		fc_slot_table;
66	struct nfs4_channel_attrs	bc_attrs;
67	struct nfs4_slot_table		bc_slot_table;
68	struct nfs_client		*clp;
69};
70
71enum nfs4_session_state {
72	NFS4_SESSION_INITING,
73	NFS4_SESSION_ESTABLISHED,
74};
75
76extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl,
77		unsigned int max_reqs, const char *queue);
78extern void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl);
79extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
80extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
81extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
82bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
83		struct nfs4_slot *slot);
84void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
85
86static inline bool nfs4_slot_tbl_draining(struct nfs4_slot_table *tbl)
87{
88	return !!test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
89}
90
91#if defined(CONFIG_NFS_V4_1)
92extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
93		u32 target_highest_slotid);
94extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
95		struct nfs4_slot *slot,
96		struct nfs4_sequence_res *res);
97
98extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
99
100extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
101extern void nfs4_destroy_session(struct nfs4_session *session);
102extern int nfs4_init_session(struct nfs_client *clp);
103extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
104
105/*
106 * Determine if sessions are in use.
107 */
108static inline int nfs4_has_session(const struct nfs_client *clp)
109{
110	if (clp->cl_session)
111		return 1;
112	return 0;
113}
114
115static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
116{
117	if (nfs4_has_session(clp))
118		return (clp->cl_session->flags & SESSION4_PERSIST);
119	return 0;
120}
121
122static inline void nfs4_copy_sessionid(struct nfs4_sessionid *dst,
123		const struct nfs4_sessionid *src)
124{
125	memcpy(dst->data, src->data, NFS4_MAX_SESSIONID_LEN);
126}
127
128#ifdef CONFIG_CRC32
129/*
130 * nfs_session_id_hash - calculate the crc32 hash for the session id
131 * @session - pointer to session
132 */
133#define nfs_session_id_hash(sess_id) \
134	(~crc32_le(0xFFFFFFFF, &(sess_id)->data[0], sizeof((sess_id)->data)))
135#else
136#define nfs_session_id_hash(session) (0)
137#endif
138#else /* defined(CONFIG_NFS_V4_1) */
139
140static inline int nfs4_init_session(struct nfs_client *clp)
141{
142	return 0;
143}
144
145/*
146 * Determine if sessions are in use.
147 */
148static inline int nfs4_has_session(const struct nfs_client *clp)
149{
150	return 0;
151}
152
153static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
154{
155	return 0;
156}
157
158#endif /* defined(CONFIG_NFS_V4_1) */
159#endif /* IS_ENABLED(CONFIG_NFS_V4) */
160#endif /* __LINUX_FS_NFS_NFS4SESSION_H */
161